<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>后盾人</title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }

        body {}


        header {
            position: fixed;
            left: 0px;
            top: 0px;
            right: 0;
            height: 60px;
            border-bottom: solid 5px blueviolet;
            box-shadow: 0 5px 10px #555;
            background: white;
            z-index: 9999;
        }

        main {
            position: relative;
            height: 3000px;
            background: red;
            margin-top: 100px;
        }
    </style>
</head>

<body>
    <header></header>
    <main></main>
</body>

</html>